Polystyrene-supported GaCl3: A new, highly efficient and recyclable heterogeneous Lewis acid catalyst for tetrahydropyranylation of alcohols and phenols
作者:Ali Rahmatpour
DOI:10.1016/j.poly.2012.06.063
日期:2012.8
highly chemoselective method for tetrahydropyranylation of alcohols and phenols with 3,4-dihydro-2H-pyran (DHP) in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewisacidcatalyst at room temperature is presented. In this catalytic system, primary, secondary and tertiary alcohols, as well as phenols, were converted to the corresponding
P4VPy–CuO nanoparticles were synthesized using ultrasound irradiations. Relevant properties of the synthesized nanoparticles were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. After identification, the prepared reagent was used for the promotion of different types of protection reactions of alcohols, phenols and amines. Easy workup, short reaction times, excellent yields, relatively low cost and reusability of the catalyst are the striking features of the reported methods.
Chemoselective trimethylsilylation and tetrahydropyranylation of benzylic and primary and secondary aliphatic alcohols proceed efficiently in the presence of 1,3-dibromo-5,5-dimethylhydantoin (DBH) under mild and completely heterogeneous reaction conditions in excellent yields.
Silylation and Tetrahydropyranylation of Alcohols Catalyzed by Al(HSO<sub>4</sub>)<sub>3</sub>
作者:Farhad Shirini、Mohammad Ali Zolfigol、Masoumeh Abedini
DOI:10.1246/bcsj.78.1982
日期:2005.11
Trimethylsilylation and tetrahydropyranylation of alcohols are efficiently catalyzed by Al(HSO4)3. All reactions were performed under mild and completely heterogeneous conditions in good-to-high yields.
Abstract In this paper, rapid and highlyefficient tetrahydropyranylation of alcohols and phenols with 3,4-dihydro-2H-pyran (DHP) in the presence of catalytic amounts of high-valent tin (IV) tetraphenylporphyrinato trifluoromethanesufonate, [Sn IV (TPP)(OTf) 2 ] is reported. In this catalytic system, primary, secondary and tertiary alcohols as well as phenols were converted to their corresponding tetrahydropyranyl